If you love pork tenderloin sandwiches, then visit the BEST TENDERLOIN SANDWICH website...
The DesLoines tenderloin blog began in September 28, 2007, and is the most extensive and serious tenderloin resource you can find (on or off the internet!). Please feel free to stay here and peruse my website below--an earlier attempt to honor the tenderloin sandwich--but you really must visit DesLoines to get your breaded pork tenderloin sandwich jones satisfied.
--Allen dont't-forget-the-mustard Bukoff

People are talking. There's quite a bit of online discussion about the breaded pork tenderloin sandwich, it's construction, natural habitat, and origins on both roadfood.com (the website for Jane & Michael Stern's Roadfood book) and on chowhound.com (search for "tenderloin" on their Midwest Message Board).

Breaded Pork Tenderloin invented in Indiana? The claim is made on epicurious.com that the breaded pork tenderloin originated with Nick Frienstein, street vendor and later owner of Nick's Kitchen, in Huntington, Indiana, in 1904. Another story--from Iowa folklore--is that the breaded pork tenderloin came out of the Czech/Bohemian community in and around Cedar Rapids,Iowa, and is derived from the central European breaded schnitzel. Regardless of its true origins, the biggest fans of the breaded pork tenderloin sandwich come from Illinois, Indiana, and Iowa--the breaded pork tenderloin's main habitat.

Love me, tenderloin
Chicago Tribune, Oct 13, 2005It's Iowa's version of a delicacy: the breaded pork tenderloin. Three Hawkeye State transplants tell you why it is a sandwich like no other--and where to find it here [Chicago area].

How many places serve breaded pork tenderloin sandwiches in Iowa? No one knows (and restaurants come and go with some regularity), but an Iowa Pork Producers Association announcement says it got 266 nominations for in this year's contest for the Best Breaded Pork Tenderloin Sandwich in Iowa. Probably some multiple nominations and maybe some franchises producing the same sandwich, so our GUESS is maybe 200 different breaded pork tenderloin sandwiches can be found in Iowa at this time. We ought to get the Iowa Pork Producers Association to publish the whole list of nominees. Then we can all just drive around Iowa eating breaded pork tenderloin sandwiches!